This invention relates to an electronic circuit block, especially to an improved electronic circuit block comprising part-receiving portions on the circuit substrate on which an integrated circuit, condenser, crystal oscillating element and the like are mounted with the upper surfaces of the respective connecting parts or terminal elements being substantially on the same level with each other. Further, an insulating layer made of polyimide resins is formed on the circuit substrate, with gaps between the parts and the part receiving portions being filled with the resins and a conductive pattern is formed on the insulated layer, whereby each of the parts or elements are connected.